The operation of reaction turbines is described by Newton's third law of motion (action and reaction are equal and opposite). In a reaction turbine, unlike in an impulse turbine, the nozzles that discharge the working fluid are attached to the rotor.
The acceleration of the fluid leaving the nozzles produces a reaction force on a turbine rotor, causing the rotor to move in the opposite direction to that of the fluid. The pressure of the fluid changes as it passes through the rotor blades. In most cases, a pressure casement is needed to contain the working fluid as it acts on the turbine; in the case of water turbines, the casement also maintains the suction imparted by the draft tube. Alternatively, where a casement is absent, the turbine must be fully immersed in the fluid flow as in the case of wind turbines.
A reaction turbine is most efficient when suitably oriented to the fluid flow. In the case, for example, of wind turbine applications, the shifting orientation of the driving wind causes fluctuating efficiency in exploiting the wind as an energy source. The most frequent means used to orient the turbines includes some form of vane in the fashion of farmyard windmill. Using a vane, however, has proven to be inefficient and achieves orientation slowly often lagging the actual orientation of the fluid flow.
Actuated orientation of turbine requires the use of rapidly performing processors and suitable sensors. Those algorithms generally use the output of the turbine using a phase-locked loop. Generally, these algorithms suffer from perennial searching loops overshooting the maxima in a manner characteristic of either under- or over-damped oscillatory systems. In either of the vaned or the actuated systems, searching inefficiencies can denigrate performance of reactive turbine as function of the available kinetic energy of the driving fluid.
There is an unmet need in the art for a self-directing turbine system efficiently deriving energy from a flowing fluid stream.